September weather forecastSumner, WI
September
Weather in September
September, the first month of the autumn in Sumner, is also an agreeable month, with an average temperature varying between 68.9°F (20.5°C) and 49.6°F (9.8°C).Temperature
A subtle change in temperatures is noted as August gives way to September, with average highs reducing from a moderately hot 76.6°F (24.8°C) to an agreeable 68.9°F (20.5°C). During September, the nighttime temperature averages of 49.6°F (9.8°C).Humidity
The average relative humidity in September in Sumner is 80%.Rainfall
In Sumner, during September, the rain falls for 12.4 days and regularly aggregates up to 1.93" (49mm) of precipitation. Throughout the year, in Sumner, there are 137.1 rainfall days, and 24.72" (628mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall in Sumner.Daylight
The average length of the day in September in Sumner is 12h and 31min.On the first day of September, sunrise is at 6:29 am and sunset at 7:43 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:48 pm CDT.
Sunshine
In September, the average sunshine in Sumner, Wisconsin, is 8.3h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: In September, the maximum UV index of 4 transforms into these recommendations:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Stay sun-safe with clothing that is both closely woven and worn loosely.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Sumner, WI
- Average high temperature in September: 68.9°F
The warmest month (with the highest average high temperature) is July (78.4°F).
The month with the lowest average high temperature is January (17.6°F).
- Average low temperature in September: 49.6°F
The month with the highest average low temperature is July (59.4°F).
The coldest month (with the lowest average low temperature) is January (5.4°F).
Average pressure in September
Sumner, WI
- Average pressure in September: 30"Hg
The months with the highest atmospheric pressure are January and February (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Sumner, WI
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is April (9mph).
The calmest months (with the lowest average wind speed) are July and August (6.6mph).
Average humidity in September
Sumner, WI
- Average humidity in September: 80%
The months with the highest relative humidity are January and February (92%).
The month with the lowest relative humidity is May (76%).
Average rainfall in September
Sumner, WI
- Average rainfall in September: 1.93"
The wettest month (with the highest rainfall) is June (3.82").
The driest month (with the least rainfall) is January (0.87").
Average rainfall days in September
Sumner, WI
- Average rainfall days in September: 12.4 days
The month with the highest number of rainy days is June (19 days).
The month with the least rainy days is February (3.6 days).
Average snowfall in September
Sumner, WI
- Average snowfall in September: 0"
The month with the highest snowfall is February (6.65").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Sumner, WI
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (18.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Sumner, WI
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in September: 8h and 18min
The month with the most sunshine is July (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 2h and 48min).
Average sunshine days in September
Sumner, WI
- Average sunshine days in September: 15.7 days
The month with the most sunshine days is October (15.9 days).
The month with the least sunshine days is June (9.4 days).
Average UV index in September
Sumner, WI
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February and December (UV index 1).
Average cloud cover in September
Sumner, WI
- Average cloud cover in September: 38
The month with the most cloud cover is January (Cloud cover 72).
The month with the least cloud cover is July (Cloud cover 35).
Average visibility in September
Sumner, WI
- Average visibility in September: 5mi
The months with the highest visibility are April, May, June and October (6mi).
The months with the lowest visibility are January, February and December (4mi).





